A public utility is an organization that maintains the infrastructure for a public service (often also providing a service using that infrastructure). Public utilities are subject to forms of public control and regulation ranging from local community based groups to state wide government monopolies.

Developments in technology have eroded some of the natural monopoly aspects of traditional public utilities. For instance, electricity generation, electricity retailing, telecommunication and postal services have become competitive in some countries and the trend towards liberalization, deregulation and privatization of public utilities is growing, but the network infrastructure used to distribute most utility products and services has remained largely monopolistic.